Illuminated signs are used in a variety of environments and serve a variety of purposes. One of the most common purposes is to provide illumination in an emergency situation. Emergency lighting capability is mandated by commercial building codes throughout most of the world. The most common type of emergency lighting is the exit sign, which is intended to be illuminated at all times and clearly direct those in flight to the nearest exit during a fire or other emergency. Exit signs are typically placed above doorways or in egress paths to indicate the most efficient manner of exiting a building. A simple “EXIT” message can be provided on a sign located directly above the egress from the building or, where the egress is located away from the sign, an “EXIT” message is normally coupled on the sign with a directional indicator, such as a chevron, that points toward the closest exit.
A variety of exit signs are available and in use today. Exit signs are typically made of die cast metal or molded of a polymer material. Moreover, the benefits of exit signs in certain environments have been enhanced by attaching additional emergency lighting on the sign housing, such as is disclosed in U.S. Pat. No. 5,797,673.
While exit signs may come in all shapes and sizes and with a variety of accessories, U.S. Pat. No. 6,152,581 discloses a representative structure of an exit sign. FIG. 1 of U.S. Pat. No. 6,152,581 (reproduced as FIG. 1 herein for ease of discussion, but with reference numerals changed) illustrates an exit sign 1 having a housing frame 2, a front cover plate 4, and a rear mounting plate 8. The front and rear plates 4, 8 attach to the housing frame 2 to form the exit sign structure, which houses the necessary components for operation such as illuminations sources, electrical circuitry, power sources (such as batteries), and other structural elements necessary to illuminate the sign.
In this example, a legend 6 (with the letters “E”, “X”, “I”, and “T”) is formed on the front cover plate 4. To ensure that the exit message legend is easily seen, a planar panel 3 is mounted on the interior surface of front cover plate 4. The panel 3 is typically made from a light-transmitting plastic that appears different from the cover plate 4, such as a transparent or translucent material, and is preferably of an eye-catching color (such as red or green) that is easily seen through the legend. In use, light is generated by a power source housed inside the exit sign 1. The light inside the exit sign 1 causes the legend 6 to glow with the color of the panel 3, rendering the exit sign 1 more noticeable, especially in the event of a power outage in the building.
Installation of illuminated signs can be difficult. For example, once the junction box has been installed, there is often a complicated hanging structure—with multiple parts—that needs to be installed over the junction box in order to secure the sign in place. Because the installer is usually standing on a ladder, having multiple parts to contend with can be difficult and time consuming.
Specifically, a mounting device, such as those disclosed in U.S. patent application Ser. No. 10/763,035 entitled “Mounting Devices for Exit Signs and Other Fixtures” connects an illuminated sign, such as an exit sign, to a junction box. Junction boxes are typically recessed within or otherwise mounted to ceilings or walls and are connected to a power source. Electrical wiring from the junction box can be pulled through the mounting device and into the interior of the sign for connecting electrical components in the sign to a main power source. Then, in order to secure the sign to the mounting device, a series of screws, bolts, and other securing devices are used. Accordingly, there is a need in the art for an illuminated sign housing that provides a greater ease of installation.
Moreover, unlike plastic signs, exit signs made from metal are relatively heavy. Thus, when mounted on a ceiling or wall, they have a tendency to sag or pull from the ceiling or wall and pull their mounting devices with them so that the junction box is exposed. Thus, attempts have been made to bias the signs toward the ceiling or wall surface from which they protrude, and thereby ensure that the junction box is covered from view in the finished installation. For example, in the past a pipe fitting was fed into a sign housing from the point of attachment (i.e., ceiling or wall). A lock washer and nut were mounted on the pipe fitting and the nut was tightened to bias the sign towards the ceiling or wall. Such an arrangement required manipulation of a number of parts and consequently increased the time and cost of sign installation. Moreover, the pipe fittings cast shadows in the sign that negatively impacted visibility of the illuminated legend. Accordingly, there is also a need in the art for illuminated signs that have a secure connection to the wall, ceiling, or other mounting surface, such that the sign can be mounted and biased toward the mounting surface to prevent any sagging.
Another challenge with current illuminated signs in that the inner components of the sign, such as illumination sources, electrical circuitry, power sources (such as batteries), and other structural elements necessary to illuminate the sign, have traditionally been mounted directly to the housing frame. Thus, should the sign housing be irreparably damaged, it is typically discarded even though the inner components are still functional. Similarly, should the inner components fail, the entire sign must be replaced even though the sign housing is still operable. Accordingly, it is desirable to provide a separate sign insert that can house inner components separately from the outer sign housing.